Case Study: Nebraska State University at Chadron
Nebraska State University at Chadron is 100 miles south of Rapid City, South Dakota. In 1990, the University installed two Hurst wood-fired boilers to replace the previous system that operated using natural gas and oil. These wood boilers heat 20 buildings, or approximately 1.1 million square feet of classrooms, dormitories, laboratories and offices.
In 2004, Chadron added absorption chillers that use surplus steam from the wood boilers for power and now use the system for both cooling and heating. The cooling system provides air conditioning for six buildings on campus, or approximately 280,000 square feet.
This system depends on a crew of eight to load and manage the system, which operates on an annual load of 8,000 tons of wood chips or approximately 20 tons a day. Wood fuel has been provided by one contractor since 1990. The wood fuel was originally wood waste from the mill operated by the contractor, but since the closure of his mill he acquires wood chips from logging slash on private lands, state school land and nearby state park land.
Source: Fuel for Schools
- Two Hurst wood-fired boilers capable of 12,000 and 6,000 psi of steam per hour.
- Auger and conveyor belt system to feed boilers.
- One Trane 700 ton chill capacity unit
Cost of System
- Heating System (1990 system: 2 boilers, building, wood storage, piping) $1.45 million
- Cooling System (2004 system addition, including additional piping) $1.3 million
Operational and Maintenance Costs
- Boiler modernization updates $116,000
- Pump system update $18,000
- Labor (8 employees at approximately $50,000) $400,000
- Wood fuel (Assuming $20 per ton and 8,000 tons used per year) $160,000
Darrell Marshell ~ 308-432-6226